#include <sys/param.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <kern/locks.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip_encap.h>
#include <net/kpi_interface.h>
#include <net/kpi_protocol.h>
#include <net/net_osdep.h>
#include <net/bpf.h>
#if CONFIG_MACF_NET
#include <security/mac_framework.h>
#endif
#define GET_V4(x) ((const struct in_addr *)(const void *)(&(x)->s6_addr16[1]))
static lck_grp_t *stf_mtx_grp;
struct stf_softc {
ifnet_t sc_if;
u_int32_t sc_protocol_family;
union {
struct route __sc_ro4;
struct route_in6 __sc_ro6;
} __sc_ro46;
#define sc_ro __sc_ro46.__sc_ro4
decl_lck_mtx_data(, sc_ro_mtx);
const struct encaptab *encap_cookie;
bpf_tap_mode tap_mode;
bpf_packet_func tap_callback;
};
void stfattach (void);
static int ip_stf_ttl = 40;
static int stf_init_done;
static void in_stf_input(struct mbuf *, int);
static void stfinit(void);
static struct protosw in_stf_protosw =
{
.pr_type = SOCK_RAW,
.pr_protocol = IPPROTO_IPV6,
.pr_flags = PR_ATOMIC|PR_ADDR,
.pr_input = in_stf_input,
.pr_ctloutput = rip_ctloutput,
.pr_usrreqs = &rip_usrreqs,
.pr_unlock = rip_unlock,
};
static int stf_encapcheck(const struct mbuf *, int, int, void *);
static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
int stf_pre_output(struct ifnet *, protocol_family_t, struct mbuf **,
const struct sockaddr *, void *, char *, char *);
static int stf_checkaddr4(struct stf_softc *, const struct in_addr *,
struct ifnet *);
static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
struct ifnet *);
static void stf_rtrequest(int, struct rtentry *, struct sockaddr *);
static errno_t stf_ioctl(ifnet_t ifp, u_long cmd, void *data);
static errno_t stf_output(ifnet_t ifp, mbuf_t m);
static void
stfinit(void)
{
if (!stf_init_done) {
stf_mtx_grp = lck_grp_alloc_init("stf", LCK_GRP_ATTR_NULL);
stf_init_done = 1;
}
}
static errno_t
stf_media_input(
__unused ifnet_t ifp,
protocol_family_t protocol_family,
mbuf_t m,
__unused char *frame_header)
{
if (proto_input(protocol_family, m) != 0)
m_freem(m);
return (0);
}
static errno_t
stf_add_proto(
ifnet_t ifp,
protocol_family_t protocol_family,
__unused const struct ifnet_demux_desc *demux_array,
__unused u_int32_t demux_count)
{
struct stf_softc* stf = ifnet_softc(ifp);
if (stf->sc_protocol_family == 0)
stf->sc_protocol_family = protocol_family;
else {
printf("stf_add_proto: stf already has a proto\n");
return EBUSY;
}
return 0;
}
static errno_t
stf_del_proto(
ifnet_t ifp,
protocol_family_t protocol_family)
{
if (((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family == protocol_family)
((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family = 0;
return 0;
}
static errno_t
stf_attach_inet6(
ifnet_t ifp,
protocol_family_t protocol_family)
{
struct ifnet_attach_proto_param reg;
errno_t stat;
if (protocol_family != PF_INET6)
return EPROTONOSUPPORT;
bzero(®, sizeof(reg));
reg.input = stf_media_input;
reg.pre_output = stf_pre_output;
stat = ifnet_attach_protocol(ifp, protocol_family, ®);
if (stat && stat != EEXIST) {
printf("stf_attach_proto_family can't attach interface fam=%d\n",
protocol_family);
}
return stat;
}
static errno_t
stf_demux(
ifnet_t ifp,
__unused mbuf_t m,
__unused char *frame_ptr,
protocol_family_t *protocol_family)
{
struct stf_softc* stf = ifnet_softc(ifp);
*protocol_family = stf->sc_protocol_family;
return 0;
}
static errno_t
stf_set_bpf_tap(
ifnet_t ifp,
bpf_tap_mode mode,
bpf_packet_func callback)
{
struct stf_softc *sc = ifnet_softc(ifp);
sc->tap_mode = mode;
sc->tap_callback = callback;
return 0;
}
void
stfattach(void)
{
struct stf_softc *sc;
int error;
const struct encaptab *p;
struct ifnet_init_params stf_init;
stfinit();
error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_STF,
stf_attach_inet6, NULL);
if (error != 0)
printf("proto_register_plumber failed for AF_INET6 error=%d\n", error);
sc = _MALLOC(sizeof(struct stf_softc), M_DEVBUF, M_WAITOK | M_ZERO);
if (sc == 0) {
printf("stf softc attach failed\n" );
return;
}
p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck,
&in_stf_protosw, sc);
if (p == NULL) {
printf("sftattach encap_attach_func failed\n");
FREE(sc, M_DEVBUF);
return;
}
sc->encap_cookie = p;
lck_mtx_init(&sc->sc_ro_mtx, stf_mtx_grp, LCK_ATTR_NULL);
bzero(&stf_init, sizeof(stf_init));
stf_init.name = "stf";
stf_init.unit = 0;
stf_init.type = IFT_STF;
stf_init.family = IFNET_FAMILY_STF;
stf_init.output = stf_output;
stf_init.demux = stf_demux;
stf_init.add_proto = stf_add_proto;
stf_init.del_proto = stf_del_proto;
stf_init.softc = sc;
stf_init.ioctl = stf_ioctl;
stf_init.set_bpf_tap = stf_set_bpf_tap;
error = ifnet_allocate(&stf_init, &sc->sc_if);
if (error != 0) {
printf("stfattach, ifnet_allocate failed - %d\n", error);
encap_detach(sc->encap_cookie);
lck_mtx_destroy(&sc->sc_ro_mtx, stf_mtx_grp);
FREE(sc, M_DEVBUF);
return;
}
ifnet_set_mtu(sc->sc_if, IPV6_MMTU);
ifnet_set_flags(sc->sc_if, 0, 0xffff);
#if 0
ifnet_set_flags(sc->sc_if, IFF_LINK2, IFF_LINK2);
#endif
#if CONFIG_MACF_NET
mac_ifnet_label_init(&sc->sc_if);
#endif
error = ifnet_attach(sc->sc_if, NULL);
if (error != 0) {
printf("stfattach: ifnet_attach returned error=%d\n", error);
encap_detach(sc->encap_cookie);
ifnet_release(sc->sc_if);
lck_mtx_destroy(&sc->sc_ro_mtx, stf_mtx_grp);
FREE(sc, M_DEVBUF);
return;
}
bpfattach(sc->sc_if, DLT_NULL, sizeof(u_int));
return;
}
static int
stf_encapcheck(
const struct mbuf *m,
__unused int off,
int proto,
void *arg)
{
struct ip ip;
struct in6_ifaddr *ia6;
struct stf_softc *sc;
struct in_addr a, b;
sc = (struct stf_softc *)arg;
if (sc == NULL)
return 0;
if ((ifnet_flags(sc->sc_if) & IFF_UP) == 0)
return 0;
if ((ifnet_flags(sc->sc_if) & IFF_LINK0) != 0)
return 0;
if (proto != IPPROTO_IPV6)
return 0;
mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip), &ip);
if (ip.ip_v != 4)
return 0;
ia6 = stf_getsrcifa6(sc->sc_if);
if (ia6 == NULL)
return 0;
IFA_LOCK(&ia6->ia_ifa);
if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
sizeof(ip.ip_dst)) != 0) {
IFA_UNLOCK(&ia6->ia_ifa);
IFA_REMREF(&ia6->ia_ifa);
return 0;
}
bzero(&a, sizeof(a));
a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr;
a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr;
b = ip.ip_src;
b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr;
if (a.s_addr != b.s_addr) {
IFA_UNLOCK(&ia6->ia_ifa);
IFA_REMREF(&ia6->ia_ifa);
return 0;
}
IFA_UNLOCK(&ia6->ia_ifa);
IFA_REMREF(&ia6->ia_ifa);
return 32;
}
static struct in6_ifaddr *
stf_getsrcifa6(struct ifnet *ifp)
{
struct ifaddr *ia;
struct in_ifaddr *ia4;
struct sockaddr_in6 *sin6;
struct in_addr in;
ifnet_lock_shared(ifp);
for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) {
IFA_LOCK(ia);
if (ia->ifa_addr == NULL) {
IFA_UNLOCK(ia);
continue;
}
if (ia->ifa_addr->sa_family != AF_INET6) {
IFA_UNLOCK(ia);
continue;
}
sin6 = (struct sockaddr_in6 *)(void *)ia->ifa_addr;
if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
IFA_UNLOCK(ia);
continue;
}
bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
IFA_UNLOCK(ia);
lck_rw_lock_shared(in_ifaddr_rwlock);
for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
ia4;
ia4 = TAILQ_NEXT(ia4, ia_link))
{
IFA_LOCK(&ia4->ia_ifa);
if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) {
IFA_UNLOCK(&ia4->ia_ifa);
break;
}
IFA_UNLOCK(&ia4->ia_ifa);
}
lck_rw_done(in_ifaddr_rwlock);
if (ia4 == NULL)
continue;
IFA_ADDREF(ia);
ifnet_lock_done(ifp);
return ((struct in6_ifaddr *)ia);
}
ifnet_lock_done(ifp);
return (NULL);
}
int
stf_pre_output(
struct ifnet *ifp,
__unused protocol_family_t protocol_family,
struct mbuf **m0,
const struct sockaddr *dst,
__unused void *route,
__unused char *desk_linkaddr,
__unused char *frame_type)
{
struct mbuf *m = *m0;
struct stf_softc *sc;
const struct sockaddr_in6 *dst6;
const struct in_addr *in4;
u_int8_t tos;
struct ip *ip;
struct ip6_hdr *ip6;
struct in6_ifaddr *ia6;
struct sockaddr_in *dst4;
struct ip_out_args ipoa =
{ IFSCOPE_NONE, { 0 }, IPOAF_SELECT_SRCIF, 0 };
errno_t result = 0;
sc = ifnet_softc(ifp);
dst6 = (const struct sockaddr_in6 *)(const void *)dst;
if ((ifnet_flags(ifp) & IFF_UP) == 0) {
printf("stf: IFF_DOWN\n");
return ENETDOWN;
}
ia6 = stf_getsrcifa6(ifp);
if (ia6 == NULL) {
return ENETDOWN;
}
if (mbuf_len(m) < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m) {
*m0 = NULL;
IFA_REMREF(&ia6->ia_ifa);
return ENOBUFS;
}
}
ip6 = mtod(m, struct ip6_hdr *);
tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
in4 = GET_V4(&ip6->ip6_dst);
else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
in4 = GET_V4(&dst6->sin6_addr);
else {
IFA_REMREF(&ia6->ia_ifa);
return ENETUNREACH;
}
if (ifp->if_bpf) {
u_int32_t af = AF_INET6;
bpf_tap_out(ifp, 0, m, &af, sizeof(af));
}
M_PREPEND(m, sizeof(struct ip), M_DONTWAIT, 1);
if (m && mbuf_len(m) < sizeof(struct ip))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL) {
*m0 = NULL;
IFA_REMREF(&ia6->ia_ifa);
return ENOBUFS;
}
ip = mtod(m, struct ip *);
bzero(ip, sizeof(*ip));
IFA_LOCK_SPIN(&ia6->ia_ifa);
bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr),
&ip->ip_src, sizeof(ip->ip_src));
IFA_UNLOCK(&ia6->ia_ifa);
bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst));
ip->ip_p = IPPROTO_IPV6;
ip->ip_ttl = ip_stf_ttl;
ip->ip_len = m->m_pkthdr.len;
if (ifp->if_flags & IFF_LINK1)
ip_ecn_ingress(ECN_NORMAL, &ip->ip_tos, &tos);
else
ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
lck_mtx_lock(&sc->sc_ro_mtx);
dst4 = (struct sockaddr_in *)(void *)&sc->sc_ro.ro_dst;
if (ROUTE_UNUSABLE(&sc->sc_ro) || dst4->sin_family != AF_INET ||
bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
ROUTE_RELEASE(&sc->sc_ro);
dst4->sin_family = AF_INET;
dst4->sin_len = sizeof(struct sockaddr_in);
bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
}
result = ip_output(m, NULL, &sc->sc_ro, IP_OUTARGS, NULL, &ipoa);
lck_mtx_unlock(&sc->sc_ro_mtx);
if (result == 0)
result = EJUSTRETURN;
*m0 = NULL;
IFA_REMREF(&ia6->ia_ifa);
return result;
}
static errno_t
stf_output(
__unused ifnet_t ifp,
__unused mbuf_t m)
{
return 0;
}
static int
stf_checkaddr4(
struct stf_softc *sc,
const struct in_addr *in,
struct ifnet *inifp)
{
struct in_ifaddr *ia4;
if (IN_MULTICAST(ntohl(in->s_addr)))
return -1;
switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
case 0: case 127: case 255:
return -1;
}
lck_rw_lock_shared(in_ifaddr_rwlock);
for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
ia4;
ia4 = TAILQ_NEXT(ia4, ia_link))
{
IFA_LOCK(&ia4->ia_ifa);
if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) {
IFA_UNLOCK(&ia4->ia_ifa);
continue;
}
if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
IFA_UNLOCK(&ia4->ia_ifa);
lck_rw_done(in_ifaddr_rwlock);
return -1;
}
IFA_UNLOCK(&ia4->ia_ifa);
}
lck_rw_done(in_ifaddr_rwlock);
if (sc && (ifnet_flags(sc->sc_if) & IFF_LINK2) == 0 && inifp) {
struct sockaddr_in sin;
struct rtentry *rt;
bzero(&sin, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_addr = *in;
rt = rtalloc1((struct sockaddr *)&sin, 0, 0);
if (rt != NULL)
RT_LOCK(rt);
if (rt == NULL || rt->rt_ifp != inifp) {
#if 1
log(LOG_WARNING, "%s: packet from 0x%x dropped "
"due to ingress filter\n", if_name(sc->sc_if),
(u_int32_t)ntohl(sin.sin_addr.s_addr));
#endif
if (rt != NULL) {
RT_UNLOCK(rt);
rtfree(rt);
}
return -1;
}
RT_UNLOCK(rt);
rtfree(rt);
}
return 0;
}
static int
stf_checkaddr6(
struct stf_softc *sc,
struct in6_addr *in6,
struct ifnet *inifp)
{
if (IN6_IS_ADDR_6TO4(in6))
return stf_checkaddr4(sc, GET_V4(in6), inifp);
if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
return -1;
return 0;
}
static void
in_stf_input(
struct mbuf *m,
int off)
{
struct stf_softc *sc;
struct ip *ip;
struct ip6_hdr ip6;
u_int8_t otos, itos;
int proto;
struct ifnet *ifp;
struct ifnet_stat_increment_param stats;
ip = mtod(m, struct ip *);
proto = ip->ip_p;
if (proto != IPPROTO_IPV6) {
m_freem(m);
return;
}
ip = mtod(m, struct ip *);
sc = (struct stf_softc *)encap_getarg(m);
if (sc == NULL || (ifnet_flags(sc->sc_if) & IFF_UP) == 0) {
m_freem(m);
return;
}
ifp = sc->sc_if;
#if MAC_LABEL
mac_mbuf_label_associate_ifnet(ifp, m);
#endif
if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
m_freem(m);
return;
}
otos = ip->ip_tos;
mbuf_copydata(m, off, sizeof(ip6), &ip6);
if (stf_checkaddr6(sc, &ip6.ip6_dst, NULL) < 0 ||
stf_checkaddr6(sc, &ip6.ip6_src, m->m_pkthdr.rcvif) < 0) {
m_freem(m);
return;
}
itos = (ntohl(ip6.ip6_flow) >> 20) & 0xff;
if ((ifnet_flags(ifp) & IFF_LINK1) != 0)
ip_ecn_egress(ECN_NORMAL, &otos, &itos);
else
ip_ecn_egress(ECN_NOCARE, &otos, &itos);
ip6.ip6_flow &= ~htonl(0xff << 20);
ip6.ip6_flow |= htonl((u_int32_t)itos << 20);
m->m_pkthdr.rcvif = ifp;
mbuf_pkthdr_setheader(m, mbuf_data(m));
mbuf_adj(m, off);
if (ifp->if_bpf) {
u_int32_t af = AF_INET6;
bpf_tap_in(ifp, 0, m, &af, sizeof(af));
}
bzero(&stats, sizeof(stats));
stats.packets_in = 1;
stats.bytes_in = mbuf_pkthdr_len(m);
mbuf_pkthdr_setrcvif(m, ifp);
ifnet_input(ifp, m, &stats);
return;
}
static void
stf_rtrequest(
__unused int cmd,
struct rtentry *rt,
__unused struct sockaddr *sa)
{
if (rt != NULL) {
RT_LOCK_ASSERT_HELD(rt);
rt->rt_rmx.rmx_mtu = IPV6_MMTU;
}
}
static errno_t
stf_ioctl(
ifnet_t ifp,
u_long cmd,
void *data)
{
struct ifaddr *ifa;
struct ifreq *ifr;
struct sockaddr_in6 *sin6;
int error;
error = 0;
switch (cmd) {
case SIOCSIFADDR:
ifa = (struct ifaddr *)data;
if (ifa == NULL) {
error = EAFNOSUPPORT;
break;
}
IFA_LOCK(ifa);
if (ifa->ifa_addr->sa_family != AF_INET6) {
IFA_UNLOCK(ifa);
error = EAFNOSUPPORT;
break;
}
sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr;
if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
if ( !(ifnet_flags( ifp ) & IFF_UP) ) {
ifa->ifa_rtrequest = stf_rtrequest;
IFA_UNLOCK(ifa);
ifnet_set_flags(ifp, IFF_UP, IFF_UP);
} else {
IFA_UNLOCK(ifa);
}
} else {
IFA_UNLOCK(ifa);
error = EINVAL;
}
IFA_LOCK_ASSERT_NOTHELD(ifa);
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
ifr = (struct ifreq *)data;
if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
;
else
error = EAFNOSUPPORT;
break;
default:
error = EOPNOTSUPP;
break;
}
return error;
}